NK cell inhibitory receptor KLRG1 (blue) binds to cadherins (purple) on target cells.
NK cells must integrate both positive and negative signals—delivered by a variety of activating and inhibitory receptors on their cell surface—to determine whether a target cell should be attacked. Many NK cell inhibitory receptors, including Ly49 receptors (mice) and killer cell immunoglobulin-like receptors (humans), bind to MHC class I molecules on target cells. This allows NK cells to distinguish between normal cells, which express class I molecules, and abnormal cells, which often lack these proteins due to transformation or viral infection. The binding partners for other inhibitory receptors, including KLRG1, had not been identified.
Ito and colleagues now...
